CASE 44 (October 2009)

Clinical information

The patient is a 26-year-old African American man who was admitted in the hospital due to 2 weeks of general malaise and weakness, without fever. He presented diarrhea and abdominal pain. On admission he had mucocutaneous pallor and mild conjunctival jaundice. Blood pressure: 120/70, heart rate: 84. There were not other alterations.

On laboratory tests: hemoglobin: 7.8%, hematocrit 23%, platelets: 75,000; leukocytes count: normal. ANAs: 1:80, Anti-DNA negative, serum complement: normal. Serum creatinine: 7.8 mg/dL, BUN: 118 mg/dL. Proteinuria: 100 mg/dL, erythrocytes: 3 / CAP.

A presumptive diagnosis of hemolytic uremic syndrome / thrombotic thrombocyopenic purpura was initially thought; however, this diagnosis was ruled out later. Hemolityc anemia was found.

A renal biopsy was undertaken. See the images.

Figure 1. H&E, X400.

Figure 2. Masson's trichrome stain, X400.

Figure 3. H&E, X400.

Figure 4. H&E, X400.

Figure 5. H&E, X400.

Figure 6. Methenamine-silver stain, X400.

Figure 7. Methenamine-silver stain, X400.

Figure 8. PAS, X400.

Direct immunofluorescence for IgA; IgG, IgM, C3, C1q, kappa, lambda, and fibrinogen: Negative.

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